Elastomeric Networks, and Their Use in Novel Nanocomposites and Related Materials

技术概述：正在进行的研究的一个实际目标是获得可用于优化弹性材料性能的结构-性能关系。实验将包括各种变形，并将进行相应的计算机模拟。弹性体将包括商业上重要的聚合物，通过各种技术进行交联。一个具体的项目将是生产具有更强取向和更好机械性能的可生物降解弹性体凝胶。另一个例子涉及应变诱导结晶的表征，它可以极大地提高材料的机械性能。新型的增强填充物，如二氧化硅，将在原位生成，产生不寻常的颗粒形状和取向，一种类型的陶瓷颗粒将被另一种类型的陶瓷颗粒覆盖。还有可能通过增强沸石来穿入弹性体链，以获得其他不寻常的性能。还将进行模拟，以阐明填充弹性体的总体增强机制，这是该聚合物科学领域中尚未解决的主要问题之一。这里特别令人感兴趣的是，当初级颗粒结合成相对稳定的结构时获得的增强的类型和程度，这些结构被称为“集合体”，并被结合成不太稳定的排列，被称为“聚集体”。作为最后一个主题，将进行实验，以开发弹性域的能力，以提高聚合物-陶瓷混杂复合材料的冲击性能，其中陶瓷是连续相。在这方面特别令人感兴趣的是，通过使用其中一个相中的网络结构的连通性来控制分散程度，以“阻止”不同的双组分系统中的常见类型的相分离。非技术概述：所描述的工作将使我们更好地了解聚合物，特别是弹性体和纳米复合材料。这最终将为制备和使用更好的弹性材料和各种类型的复合材料提供重要的指导。结果将以通常的方式在期刊出版物和各个科学或工程学会的全国会议上发表演讲中传播。更广泛的影响，将包括整合研究和教学。弹性材料表现出的橡胶状弹性是其最显著的特征之一，申请者将继续在课堂演示、实验室课程实验和标准物理化学概念的修改中利用这一点。从这些项目中获得的实验、模拟和理论的结果将继续包括在辛辛那提大学教授的弹性课程中，以及申请人自1972年以来一直教授的一些美国化学学会的短期课程中。

TECHNICAL SUMMARY:One practical goal of the research being carried out is to obtain structure-property relationships that can be used to optimize the properties of elastomeric materials. Experiments will include a variety of deformations, and corresponding computer simulations will be carried out as well. Elastomers will include commercially important polymers, cross linked by a variety of techniques. One specific project will be producing biodegradable elastomeric gels of enhanced orientation and improved mechanical properties. Another example involves characterization of strain-induced crystallization, which can greatly improve the mechanical properties of a material. Novel reinforcing fillers such as silica will be generated in-situ, yielding unusual particle shapes and orientations, and ceramic particles of one type will be coated by a ceramic of another type. It will also be possible to thread elastomeric chains through reinforcing zeolites, to obtain other unusual properties. Simulations will also be carried out to elucidate reinforcing mechanisms in filled elastomers in general, which is one of the major unsolved problems in this area of polymer science. Of particular interest here is the types and extents of reinforcement obtained when the primary particles are bonded into relatively stable structures called "aggregates" and into less-stable arrangements called "agglomerates". As a final topic, experiments will be carried out to exploit the ability of elastomeric domains to improve the impact resistances of polymer-ceramic hybrid composites in which the ceramic is the continuous phase. Of particular interest in this regard is control of the level of dispersion by using the connectivity of network structures in one of the phases to "frustrate" the usual types of phase separation in disparate two-component systems. NON-TECHNICAL SUMMARY:The work described will provide a better understanding of polymers in general and elastomers and nanocomposites in particular. This will ultimately lead to guidance important for the preparation and utilization of better elastomeric materials and various types of composites. Results will be disseminated in the usual way, in journal publications and lecture presentations at National Meetings of various scientific or engineering societies. Broader impacts, would include integrating research and teaching. The rubberlike elasticity exhibited by elastomeric materials is one of their most striking features, and the applicant will continue to exploit this in demonstrations during lectures, experiments in laboratory courses, and in the modification of standard physical chemistry concepts. Results from experiments, simulations, and theory obtained in these projects will continue to be included in the elasticity course taught at the University of Cincinnati, and in some of the American Chemical Society Short Courses the applicant has taught since 1972.